[GHC] #10034: Regression in mapM_ performance

[GHC]

#10034: Regression in mapM_ performance
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        Reporter:  dfeuer            |                   Owner:  bgamari
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:  7.12.1
       Component:  Core Libraries    |                 Version:  7.10.1-rc2
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:  Phab:D632
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Comment (by bgamari):

 David, I don't suppose you have stumbled upon an example of this in the
 months, have you?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10034#comment:9>
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